There is a growing need to carry out the three-dimensional reconstruction of a sample such as a semiconductor or an advanced material by using a charged particle beam apparatus, in particular, a transmission electron microscope (TEM), to thereby perform failure analysis on the basis of the three-dimensional structure of the sample. In order to carry out the three-dimensional reconstruction, a series of images which is photographed by tilting the sample in steps of a few degrees (tilted series images) is required. The sample used at this time has a size of approximately 1 μm and has a pillar-like shape in many cases.
Patent Literature 1 (JP Patent Publication (Kokai) No. 2004-87214 A) discloses that a pillar-like sample is mounted on a 360-degree rotatable pillar holder, and is observed at several 10,000-fold magnification or higher.
In addition, Patent Literature 2 (JP Patent Publication (Kokai) No. 07-176285 A (1995)) discloses focus correction based on a degree of sharpness.